OFFSET
0,2
FORMULA
a(n) = Sum_{k=0..n} (Product_{j=0..k-1} (2*j-3)) * Stirling2(n,k).
PROG
(PARI) a(n) = sum(k=0, n, prod(j=0, k-1, 2*j-3)*stirling(n, k, 2));
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Seiichi Manyama, Sep 05 2024
STATUS
approved